Increasing use has been made in recent years of electrical steel making principles to produce steel from scrap and such scrap replacements as directly reduced iron and molten crude iron. The conventional furnace for this purpose uses either an electric arc, for example, as a scrap smelting medium or is formed as a converter operating with about 80% molten crude iron.
A known process from DE 44 34 369 A1 alternates oxygen blowing and electric arc melting in two neighboring furnace vessels. A drawback of this system is the long cycling time and the consequent high energy loss and the high degree of iron oxide formation. The long cycling time is a consequence of the time required for replacement of the oxygen blowing lance by the electrodes for the electric arc smelting and vice versa. Further drawbacks reside in the unsatisfactory oxygen blowing and the high degree of spraying of the melt onto the furnace roof.
DE 195 26 704 C1 describes a process in which electrode smelting and oxygen blowing is carried out alternately in a single furnace vessel with the drawback that the electrode stroke is considerable and leads to long cycling times.
Another disadvantage of conventional electronic arc smelting processes is that dioxin may be liberated in the gases which are discharged and to pyrolytically decompose the dioxin, an additional burner may be required.